PART III. ] THE MECHANISMS OF FLOWERS. 143 
| eeking it must wipe off pollen from the anthers in young flowers 
‘and apply it to the stigmas in older ones. In Malva silvestris, 
which attracts insects by the larger size and brighter colour of 
its flowers, and receives very numerous visits, the ends of the 
f laments, before the stigmas are mature, curl outwards so far 
that spontaneous self-fertilisation is impossible. MJ. rotundifolia, 
whose much smaller and paler flowers attract few insects, regu- 
arly fertilises itself in default of insect-visits, for its anthers 
emain extended in such a position as to be touched by the 
papillate sides of the curling stigmas. (Fig. 44, 5). 
The following lists of insects which I have observed dur- 
‘ing four summers upon the two forms, show how great is the 
difference in this respect between them. 
i 
\ i), 
Fig, 44. 
_1—4.—Malva silvestris. 1, essential organs from a bud; 2, ditto, in the first stage of the flower 
ditto, between the first and second stages ; 4, ditto, in the second stage. 
i 5. —Malva rotundifolia in the act of self-fertilisation, 
69. MALVA SILVESTRIS, L. :— 
Visitors: A. Hymenoptera—(a) Apidw: (1) Apis mellifica, L. §,s., very 
/ ab. ; (2) Bombus lapidarius, L. 2, ab. ; (3) B. hortorum, L 9 ; (4) B. silvarum, 
L. 2; (5) B. agrorum, F.$; (6) Cilissa hamarrhoidalis, F,? ¢, freq. ; 
(7) Andrena parvula, K. ¢; (8) A. Gwynana, K. 2; (9) A. fulvicrus, K. 9° ; 
| 10) Halictus maculatus, Sm. 9; (11) H. albipes, F. 2 ; (12) H. morio, F. ? ; 
13) H. Smeathmanellus, K. 9; (14) H. zonulus, Sm. ¢; (15) Nomada late- 
Talis, Pz. 2; (16) Osmia enea, L. ¢; (17) Megachile Willughbiella, K. ¢. ; 
(18) M. ligniseca, K. ¢; (19) Coelioxys simplex, Nyl. 9 ¢; (20) Chelostoma 
-campanularum, L. ¢,—all these twenty species though always dusted with 
| pollen, never collected it, but came for honey only ; (21) Ch. nigricorne, Nyl. 
. 6 @, very ab., both s. and ep., this is the only species which I have seen 
collecting the pollen ; (22) Prosopis hyalinata, Sm. ¢; (23) P. communis, 
Nyl. 6 2, freq.; (24) P. signata, Schenck, ¢; (25) P. pictipes, Nyl. ¢; 
(26) P. dilatata, K. ¢, all sucking ; (b) Ichneumonide : (27) various species,— 
Tam unable to say whether they succeeded in reaching the honey. B. Diptera 
-(a) Stratiomyide : (28) Sargus cuprarius, L. (seemed to derive no advantage 
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